The present invention relates to apparatus for stacking articles such as cans and arranging the same in a preselected array on a stacking platform.
In stacking articles such as cans on pallets for storage and transport, it is desirable to arrange the cans in a selected space-saving configuration. This requires, in part, that the array of stacked cans on the pallet be selected to optimize the number of cans of a particular size which can be stacked on a pallet of a particular dimension, as will be explained herebelow. Secondly, in palletizing cans having bails attached thereto by projecting ears, it is advantageous to orient the cans in a preselected direction which avoids contact between such bails and adjacent cans.
Can palletizing apparatus which is designed to accomplish the latter bail-orienting prior to transferring the cans to a stacking platform is detailed in U.S. Pat. No. 3,902,594. Briefly describing this apparatus, it includes a loading, or receiving station onto which cans are loaded, in a compact linear array, by an infeed conveyor, and a vertically shiftable stacking platform. Interposed between the loading station and the conveyor is a can-orienting device which is operable to rotate the cans to have a preselected desired orientation with respect to the can bails. A transfer carriage horizontally shiftable between the loading area and the stacking platform has mounted thereon, in a fixed registry corresponding to the spacing between cans in the loading station, a plurality of power-operated gripping devices.
In operation, the gripping devices are actuated to grip a row of cans in the loading station, the loaded transfer carriage is shifted to a suitable position overlying the stacking platform, and the gripping devices are actuated to release the cans onto a pallet supported on the stacking platform. Because the gripping devices in the just-described apparatus are mounted in fixed registry, the configuration of each layer of cans stacked on the pallet is necessarily a square or rectangular array of aligned rows and columns. Such array may be optimal for certain sizes of cans loaded on certain sizes of pallets. Generally, however, a stacking arrangement having offset adjacent rows, with the cans in each row being spaced apart, will be more space-efficient.
The palletizing apparatus of the present invention is designed for stacking cans in variable, preselected arrays. Related to this feature, the apparatus is adaptable to palletize cans of one of a variety of can diameters. A further important feature of the apparatus is a height-sensing mechanism whereby the machine can palletize cans of various heights without operator control.
The apparatus of the present invention includes a loading station having provision for can orienting, a vertically shiftable stacking platform, and a transfer carriage shiftable along a horizontal path between the loading station and the stacking platform. In addition, and unlike the palletizer described in the above-cited U.S. patent, the present invention includes a subcarriage mounted on the transfer carriage for vertical shifting relative thereto. A plurality of carriers are mounted on the subcarriage for shifting along a horizontal path substantially perpendicular to the direction of the first-mentioned horizontal path. Mounted on each carrier for shifting therewith is an article-gripping device including a powered assembly mounted for limited vertical displacement relative to the associated carrier, and gripping members operatively connected to the assembly for movement, under the control thereof, between gripping and release positions.
The apparatus further includes a sensor positioned on at least one of the carriers for sensing upward movement of the associated powered assembly relative to the carrier. This sensor is connected to a control device used in controlling the extent of shifting of the subcarriage in a downward direction and movement of the gripping members between gripping and release positions in response to information from the sensor.
One important object of the present invention is to provide novel apparatus for stacking articles such as cans in a preselected array on a stacking platform.
Another object of the present invention is to provide, in such a can palletizer, a novel height-sensing mechanism whereby the palletizer can palletize cans of various heights without operator adjustment.
Yet another object of the invention is to provide a can palletizer adaptable to palletize cans having one of a variety of diameters.
More generally, it is an object of the invention to provide a can palletizer capable of receiving cans of various sizes and heights and stacking these in preselected, variable configurations, or arrays, which are optimally space-saving.
These and other objects and features of the present invention will become more fully apparent when read in connection with the following detailed description of a preferred embodiment of the invention and the accompanying drawings.